Floating roof



Jan. 16, 1951 c. M. ORR ET AL 2,538,032

FLOATING ROOF Filed Nov. '7, 1945 2 Sheets-Sheet l Jam 16, 1951 c, ORR ETAL 2,538,032

FLOATING ROOF Filed Nov. '7, 1945 2 Sheets-Sheet 2 Patented Jan. 16, 1951 FLOATING ROOF Glifiord M. Orr and Fred L.

111., assignors to Goldsby, Chicago,

Chicago Bridge & Iron Company, a corporation of Illinois Application November 7, 1945, Serial No. 627,144

3 Claims.

This invention relates to a high deck floating roof of improved design.

A; high deck floating roof is one in which a portion of the deck is normally maintained above the surface of the liquid to provide a permanent gas retaining space beneath it. In such forms of roof, it is preferable to have a central pontoon and an annular pontoon at the outside of the roof, the gap between the two pontoons being bridged by a single deck. It has heretofore been suggested that this deck should slope inwardly from the annular pontoon to the central pontoon to provide a drainage space adjacent the central pontoon. It has also been suggested that the deck may be caused to slope the other way providing it is attached to the top of the annular pontoon and a drainage space is provided by a reverse curve in the single deck.

In structures of these suggested types the annular pontoon is designed to carry the major portion of the weight of the single deck portion.

It has now been discovered that an improved structure may be produced in which the drain trough is located adjacent the annular pontoon, and the single deck portion is attached to the bottom portion of the annular pontoon. In the preferred form of the present structure all or a major portion of the weight of the single deck is carried by the central pontoon under all normal circumstances and the annular pontoon acts as a stabilizer.

The invention will be described as related to the embodiments shown in the accompanying drawings. Of the drawings Fig. l is a plan view of a floating roof tank having a floating roof embodying the invention; Fig. 2 is a vertical section along the line 2-2 of Fig. 1; Fig. 3 is a plan view of an alternate embodiment of the invention; and Fig. 4 is a vertical section taken along line 44 of Fig. 3.

The embodiment shown in Figs. 1 and 2 comprises a tank shell l0 having a floating roof i l therein floating on top of a stored liquid l2.

The floating roof I l comprises a single deck i3 sloping outwardly from the center. Beneath the deck l3 there is positioned a circular central pontoon l4, while at the outer edge of the deck there is located an annular trough l5. Adjacent this trough is an annular outer pontoon iii of slightly smaller outer diameter than the shell l0. Any

suitable sealing means may be provided between the outer surface of the annular pontoon It and the inner surface of the shell ID.

The annular trough l5 has a bottom sloping to a lowest drain portion l! to which is connected a 2 drain hose Hi. This drain hose may be any of the usual type, such as one that drains to the outside of the tank or to the bottom of the tank. The floating roof as shown provides an annular permanent gas retaining space is surrounding the central pontoon l4.

In the embodiment shown in Figs. 3 and 4 there is provided the shell Ill, an annular pontoon l6, and the central pontoon M together with the annular trough l5. This trough is spaced inwardly from the annular pontoon I B, and the deck 2! slopes from the annular pontoon Hi to the trough l5 and from the top of the central pontoon I 4 to the trough I5. In this embodiment there is also provided an emergency drain 2!] in addition to the permanent drain Ill. The emergency drain is located nearer the central pontoon l4 and is adapted to operate only when the permanent drain becomes clogged. The location of the emergency drain 2!] will depend upon the maximum total load of water that the pontoons will support.

In both embodiments of the invention the central pontoon provides the major support for the deck, while the annular pontoon acts principally as a stabilizer. However, the annular pontoon may be designed to support a small portion of the deck. Thus in the embodiment shown in Figs. 3 and 4 the annular pontoon l6 supports that portion 2| of the deck between the pontoon and the drain trough 55, while the central pontoon M supports that portion 22 of the deck between the central pontoon and the trough l5. Some support, however, will be supplied by the liquid itself when the vapor space beneath the deck is small and the liouid is in contact with the deck.

In both embodiments of the invention pipes 23 are provided connecting the vapor spaces adjacent the annular pontoon and the area between the trough and central pontoon. In the first embodiment (Fig. 2) the pipe 23 extends through the trough l8 while in the second embodiment (Fig. 4) the pipe is on top of the deck and connects the highest part of the deck portion 2] between the annular pontoon l6 andthe trough l5 to the deck adjacent the central pontoon l4. Vapor forming under the annular pontoon will tend to flow through the pipes to the vapor space around the central pontoon. If the vapor space is relatively large there will also be some vapor under and adjacent the annular pontoon but most of the vapor will be adjacent the central pontoon. Although only one pipe is shown in each embodiment others may be provided if desired.

pontoon and secured to the annular pontoon at its bottom and to the centra1 pontoon at its top, the buoyancy of the central pontoon being sufficient to support substantially the entire weight of the singl deck to provide a permanent gas retaining space beneath the single deck portion, and an annular drain trough adjacent the bottom of the annular pontoon.

2. A floating roof comprising a central pontoon, an annular pontoon at the rim of the roof, a

single deck bridging the gap between the annular pontoon and the central pontoon and secured to the annular pontoon at its bottom and to the central pontoon at its top, the buoyancy of the central pontoon being sufficient to support substantially the entire weight of the single deck to provide a permanent gas retaining space beneath the single deck portion, and an annular drain trough adjacent the bottom of the annular pontoon.

3. A floating roof comprising a central pontoon, an annular pontoon at the rim of the roof, said annular pontoon having a bottom sloping upwardly and inwardly, a single deck bridgin the gap between the annular pontoon and the central pontoon, an annular drain trough in the deck, said deck having a first portion secured to the annular pontoon near its bottom and sloping downwardly therefrom to the drain trough and said deck having a second portion sloping upwardly from the drain trough to the central pontoon and being secured to the central pontoon near its top, the buoyancy of the central pontoon being sufficient to support substantially the entire weight of the second portion of the deck and the buoyancy of the annular pontoon being sufficient to support substantially the entire Weight of the first portion of the deck, and a passage connecting the space beneath the first deck portion with the space beneath the second deck portion.

CLIFFORD M. ORR. FRED L. GOLDSBY.

REFERENCES CITED The following references are of record in-the file of this patent:

UNITED STATES PATENTS Number Name Date 1,816,868 Larson June 7, 1932 2,287,213 Wiggins June 23, 1942 2,321,058 Wiggins June 8, 1943 2,386,022 Wiggins Oct. 2, 1945 2,464,786 Allen Mar. 22, 1949 

